Question

Why is water not used instead of mercury thermometer when it is easily available to us

Answer 1

·         The melting point of water is 0oc but mercury freezing point (melting point) -38.83oc, the boiling point of the mercury is 356.73oc. The water boiling point is 100oc. so based on this criteria the merucury having the temperature reading capacity compared to water.

·         The colour of mercury is silvery so can identify easily

·         The thermal expansion of mercury is 60.4 µm/(m·K) (at 25 °C). The thermal expansion of water is from 4 oC to 100 oC - 4.2x10-2 the volumetric temperature expiation is non-linear respective to the temperature. But the mercury is linear temperature expantion can observe. This is main reason to use of mercury in the thermometers.

·         The water having the property of condensation but the mercury have no condensation property so the mercury will give exact values compared to water.

·         We can measure the negative and positive temperature by using the mercury but we can’t measure with water. Below 0oC and above 100oC can’t measure by using the water.

·         The most metals are solids at room temperature but the mercury is liquid form because it has high coefficient of expansion.

·         The mercury does not sticking to capillary wall of thermometer can easily measure temperature accurately. 

Answer 2

Answer:

here is your answer mate

Explanation:

Water cannot be used in thermometer because of its higher freezing point and lower boiling point than other liquids . ... This range is very small as compared to other liquids as mercury , having freezing point about −39oC and boiling point 356oC .